In a Go template, sometimes the way to pass the right data to the right template feels awkward to me. Calling a template with a pipeline parameter looks like calling a function with only one parameter.
Let's say I have a site for Gophers about Gophers. It has a home page main template, and a utility template to print a list of Gophers.
http://play.golang.org/p/Jivy_WPh16
Output :
*The great GopherBook* (logged in as Dewey)
[Most popular]
>> Huey
>> Dewey
>> Louie
[Most active]
>> Huey
>> Louie
[Most recent]
>> Louie
Now I want to add a bit of context in the subtemplate : format the name "Dewey" differently inside the list because it's the name of the currently logged user. But I can't pass the name directly because there is only one possible "dot" argument pipeline! What can I do?
You could register a "dict" function in your templates that you can use to pass multiple values to a template call. The call itself would then look like that:
{{template "userlist" dict "Users" .MostPopular "Current" .CurrentUser}}
The code for the little "dict" helper, including registering it as a template func is here:
var tmpl = template.Must(template.New("").Funcs(template.FuncMap{
"dict": func(values ...interface{}) (map[string]interface{}, error) {
if len(values)%2 != 0 {
return nil, errors.New("invalid dict call")
}
dict := make(map[string]interface{}, len(values)/2)
for i := 0; i < len(values); i+=2 {
key, ok := values[i].(string)
if !ok {
return nil, errors.New("dict keys must be strings")
}
dict[key] = values[i+1]
}
return dict, nil
},
}).ParseGlob("templates/*.html")